Exhibit 4.77



Credit Facility



This Credit Facility Agreement is dated 21st March 2003 and is made between Slough Trading Estate Limited (the
Lender) an English limited company, Tipperary Oil & Gas Australia PTY LTD (ACN 077536871) (the Borrower) a Queensland, Australia corporation and Tipperary Corporation (the Guarantor) a Texas, USA
corporation.





Under the terms and conditions hereunder Lender agrees to make available to Borrower a Credit Facility (the Credit Facility):



|1. |  | Total Amount
|-- |  | ------------



AUD$27,500,000. (Twenty Seven Million Five Hundred Thousand Australian dollars).



|2. |  | Purpose
|-- |  | -------



This facility shall be used for Gas Exploration, development, production and overheads related to the Comet Ridge project in
Queensland, Australia.



|3. |  | Term
|-- |  | ----



Subject to the provisions of sections 7 and 10 below, the facility shall be available from the date of this Agreement until April 2nd
2012.



|4. |  | Drawdown Request
|-- |  | ----------------



The Borrower may drawdown on this Credit Facility in amounts of A$1 million and multiples thereof or any other amount agreed by the Lender
provided the facility Total Amount is not exceeded. Drawdown requests must be received by the Lender by 10am, London time, at least three full business days before the date funds are required. Any drawdown request must be transmitted to the Lender
by facsimile to number 44 1753 517597 and should be marked attention Slough Estates Treasury. The faxed drawdown request should be signed by authorised officers of the Borrower and must include full details of the Borrowers bank
account where the proceeds are required. Funds will not be remitted direct to any party other than the Borrower.



|5. |  | Interest & Fees
|-- |  | ---------------



An up-front arrangement fee of A$100,000 is payable by the Borrower and will be deducted by the Lender from the proceeds of the initial
drawdown.



Interest will be charged at 13% per
annum on the daily outstanding balance payable quarterly on 31st March, 30thJune, 30thSeptember and 31stDecember or the next working day calculated on 365 day actual days elapsed basis. Withholding tax at 10% (or the then current rate) should be deducted from the interest flow by Borrower and paid over to the relevant
Australian Tax Authority. Evidence of the withholding tax deducted should be obtained from the Australian Tax Authority by the Borrower and forwarded to Lender as soon as practicable.



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|6. |  | Security and other indebtedness
|-- |  | -------------------------------



So long as any drawings under the facility are outstanding the Borrower is not to grant any mortgage, charge, pledge, lien, hypothecation
or any right conferring a priority of payment in respect of any obligation of any person without first obtaining the prior written consent of the Lender. This does not apply to any lien arising by operation of law or in the ordinary course of
trading or any that was already in place as at the date of this Agreement or any that arises or is granted pursuant to or is permitted under the Loan Documents as that term is defined in the First Amended and Restated Credit Agreement
dated as of February 2nd2001 between Borrower, TCW Asset Management Company and others, as amended (the TCW
Loan Documents).



Borrower will not
procure, negotiate or take on any additional third party indebtedness either secured or unsecured without the prior written consent of Lender. This does not apply to any indebtedness arising as permitted under the TCW Loan Documents or owed to the
Guarantor or Tipperary Oil & Gas Corporation.



|7. |  | Repayment & Prepayment
|-- |  | ----------------------



| | i) |  | This Credit Facility falls due for repayment in full on April 2nd 2012.
| | -- |  | -----------------------------------------------------------------------



| | ii) |  | On giving 7 days prior notice to Lender and with the prior written consent of TCW (to the extent that any monies remain due under the TCW Loan Documents) the
Borrower may repay the loan in full or in part on any quarter interest payment date. Amounts repaid are cancelled and may not be redrawn.
| | --- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iii) |  | The Lender may, at any time serve 18 months notice of cancellation of the Credit Facility. During this 18 month notice period the Credit Facility remains fully
available to the Borrower up to the Total Amount less any Prepayments. On expiration of the notice period the Borrower will arrange to repay all advances and interest due thereon and the Credit Facility will be deemed cancelled. This clause 7 (iii)
is only available to Lender once all monies owed under the TCW Loan Documents have been paid, or if not, then TCWs prior written consent is required.
| | ---- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iv) |  | Once all monies owed under the TCW Loan Documents have been paid and upon the occurrence at any time of any Event of Default, and that Event not have being rectified
within 14 days the Lender may by written notice to the Borrower demand repayment of the facility in full together with interest accrued to date with immediate effect.
| | --- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|8. |  | Change in Circumstances
|-- |  | -----------------------



If at any time it has become, or becomes apparent that it is, unlawful or contrary to any directive of any agency of any Relevant
Jurisdiction for the Lender, Borrower or the Guarantor (the `Affected Party) to allow all or part of the facility to remain outstanding, and/or to carry out all or any of its other obligations under this agreement arising upon acceptance of
this offer, upon the Affected Party notifying the other party:



| | i) |  | the Loan shall be cancelled; and
| | -- |  | --------------------------------



| | ii) |  | The Borrower shall forthwith upon demand by the Lender prepay the facility with accrued interest thereon.
| | --- |  | ---------------------------------------------------------------------------------------------------------

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|9. |  | Non Assignment
|-- |  | --------------



This Agreement is personal to the parties hereto and shall not be capable of assignment by either of them to any other party.



|10. |  | Events of Default
|--- |  | -----------------



Once all monies due under the TCW Loan Documents have been paid then:



upon the happening of any of the events specified in this clause and it / them not being rectified within 14
days the facility together with all accrued interest and other charges, shall immediately become due and repayable:



| | i) |  | If the Borrower makes a default in the payment of any monies which may have become due under the facility.
| | -- |  | ----------------------------------------------------------------------------------------------------------



| | ii) |  | If a distress, attachment, execution or other legal process is levied, enforced or sued out on or against the assets of the Borrower and is not discharged within
seven days of being levied.
| | --- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iii) |  | If the Borrower is unable to pay its debts as they fall due, stops, suspends or threatens to stop or suspend payment of all or a material part of its debts, begins
negotiations or takes any proceedings or other step with a view to readjustment, rescheduling or deferral of all or any material part of its indebtedness, proposes or makes a general assignment or an arrangement with or for the benefit of its
creditors; or if the Borrower ceases or threatens to cease to carry on its business or substantially the whole of its business.
| | ---- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iv) |  | If any indebtedness or obligation for the repayment of any monies borrowed or guaranteed by the Borrower shall become due and payable prior to the specified maturity
date thereof due to any default thereunder or is otherwise not paid when due.
| | --- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | v) |  | If an order is made or an effective resolution passed for the winding up of the Borrower, other than for the purposes of reconstruction or amalgamation, the terms of
which the Lender has previously agreed in writing.
| | -- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | vi) |  | If any present or future security on or over the assets of the Borrower becomes enforceable and any step (including the taking of possession or the appointment of a
receiver, manager or similar officer) is taken to enforce that security.
| | --- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | vii) |  | If the Borrower defaults under Clause 6 above.
| | ---- |  | ----------------------------------------------



| | viii) |  | If the Borrower is no longer ultimately controlled by Slough Estates plc.
| | ----- |  | -------------------------------------------------------------------------



The Borrower will notify the Lender in writing immediately upon the occurrence of any of the events of
default specified in this clause.



|11. |  | Miscellaneous
|--- |  | -------------



| | i) |  | The Borrower will reimburse the Lender on demand in respect of any reasonable expenses, taxes (excluding withholding tax as deducted and paid to the Australian
Tax Authority under the terms of clause 5) or levies of whatsoever nature that may
| | -- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



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be incurred by the Lender in making, maintaining, servicing, amending or enforcing the terms of this Facility.



| | ii) |  | This agreement shall be subject to the Laws of England.
| | --- |  | -------------------------------------------------------



|12. |  | Notices & Points of Contact
|--- |  | ---------------------------



For Tipperary Oil & Gas (Australia) PTY LTD: Tipperary Oil & Gas (Australia)PTY LTD, 633 Seventeenth Avenue, Suite 1550, Denver,
Colorado. Fax 303-292-3428, Telephone 303-293-9379. Attention David L. Bradshaw President and CEO and Joseph Feiten, CFO e-mail jfeiten@tipperarycorp.com



For Tipperary Corporation: Same contact details as above.



For Slough Trading Estate Limited: Slough Estates Group
Treasury Dept, 234 Bath Road Slough Berks SL1 4EE UK. Facsimile number 44-1753-517597. Telephone 44-1753-537171. Attention T.C.Mant Group Treasurer. E-mail: treasury@sloughestates.co.uk



|13. |  | Guaranty
|--- |  | --------



All obligations and liabilities of the Borrower in respect to this Credit Facility are subject to the irrevocable continuing guaranty of
the Guarantor. Guarantor is to settle on first written demand by Lender any sums due to it under the terms of this Agreement which remain unpaid by Borrower for more than 14 days after when due.



|14. |  | Conditions Precedent
|--- |  | --------------------



Prior to the first drawdown from this Credit Facility:



| | i) |  | Borrower will provide Lender with a certified true copy Board Minute approving entry into this Credit Facility and authorising an officer to sign this Credit
Facility Agreement on behalf of the Borrower.
| | -- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | ii) |  | Borrower will provide Lender with a certified true copy of the signature of the person authorised to sign this Credit Facility Agreement on behalf of Borrower.
| | --- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iii) |  | Borrower will provide Lender with certified true copies of the signatures of the persons authorised to issue drawdown notices in respect to advances under this
Credit Facility.
| | ---- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | iv) |  | A certified true Board Minute of the Guarantor approving entry into this Credit Facility acknowledging its role as guarantor and authorising an officer to sign this
Credit Facility Agreement on behalf of the Guarantor will be provided to Lender.
| | --- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | v) |  | Guarantor will provide Lender with a certified true copy of the signature of the person authorised to sign this Credit Facility Agreement on behalf of Guarantor.
| | -- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------



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In witness whereof this
Agreement has been entered into on the date stated at the beginning of this Agreement.





|Signed for and on behalf of Tipperary Oil & Gas (Australia) PTY LTD |  | Signed for and on behalf of Slough Trading Estate Limited
|------------------------------------------------------------------- |  | ---------------------------------------------------------
|                                                                   
|By                                                                  |  | /s/     David L. Bradshaw                                
|                                                                    |  | Director                                                 
|                                                                   
|Signed for and on behalf of Tipperary Corporation                   |  |                                                          
|                                                                   
|By                                                                  |  | /s/     David L. Bradshaw                                
|                                                                    |  | Director